Image forming devices, such as printers, photocopy machines, facsimile devices, multifunction peripherals having a printer part and a scanner part, and the like, include an image forming unit that forms a developer image on a print medium, such as sheet and the like, using a developer, such as toner. To the image forming unit, toner cartridges are provided as developer containers.
In addition, a toner cartridge is known that is configured removably with respect to the image forming unit (see, for example, JP Laid-Open Patent Application No. 2009-134032). As such a cartridge, there are a toner cartridge that is pre-equipped to the image forming device and a toner cartridge having various toner capacity to which a large or small amount of toner can be added depending on the user's printing frequency. These contribute in increasing the user's convenience.
An outer cartridge that configures an external member of the toner cartridge is generally a resin product from a view point of being light weight and securing freedom of a shape as a product. Therefore, the outer cartridge is mainly formed by a resin that has a good flowability, such as polystyrene, for forming in a cylindrical shape. Especially, in order to make it with a small weight, it is preferable to thin the wall as much as possible.
To prevent the toner leakage, the toner cartridge is highly airtight. Therefore, the toner cartridge is seldom provided with a hole for ventilating air, in addition to the toner ejection opening.
At the time of replacing the toner cartridge, it is necessary to hold the outside surfaces of the outer cartridge that accommodates toner inside the space therein.
However, because the outer cartridge is formed by a thick resin material in the cylindrical shape so as to maintain the shape, a pressure applies to the inside of the outer cartridge as the outer cartridge warps, when the user firmly hold the outer surface of the outer cartridge at the time of replacing the toner cartridge. As a result, there is a problem that air inside flows from an opening part of the toner cartridge, which is an opening for supplying toner to the development part, causing the toner remaining inside the toner cartridge or the toner attached to the periphery of the opening part to be scattered and leaked from the toner cartridge.
The present considers the above-described problem. An object of the present application is to prevent the developer from being scattered and leaked from the toner cartridge when the developer container is held.